Thiazoleazophenylaminoethyl carbonyloxy-C8 -C10 -alkyl compounds useful as dyes for polyester fibers

ABSTRACT

This invention relates to thiazoleazophenylaminoethyl carbonyloxy-C8-C10-alkyl compounds useful as dyes for polyester fibers represented by the formula:  &lt;IMAGE&gt;  wherein X represents hydrogen, chlorine, methyl, methoxy or ethoxy; Y represents methyl, acetylamino or propionylamino; and R1 represents C8-C10 alkyl.

This application is a continuation of application Ser. No. 583,216, filed Feb. 24, 1984, now abandoned.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to monoazo dyestuffs for polyester fibers. More specifically, it relates to monoazo dyestuffs which dye polyester fibers in blue colors excellent in various fastness properties, in particular, light fastness, sublimation fastness, washing fastness, perspiration fastness and water fastness, and which are also excellent in heat resistance and alkali discharge printing properties.

2. Description of the Prior Art

Recently, an alkali discharge printing process has been increasingly frequently carried out as a new dyeing process for polyester fibers. The principle of the alkali discharge printing is to hydrolyze a dyestuff with alkali, thereby depriving it of its affinity to polyester fibers.

Therefore, the dyestuffs intended for that purpose contain carboxylate ester groups, hydroxyl groups etc. which have great hydrophilic properties and are easily reactive with alkali in their backbone structure. For that reason, they had a disadvantage that their moisture fastness, such as washing fastness, perspiration fastness, water fastness etc. and also heat resistance were poor. The present inventors have been intensively studying in order to develop blue dyestuffs having good alkali discharge printing properties and also having good moisture fastness and heat resistance, and finally have solved this antithetical contradiction in principle, thereby having accomplished this invention.

Although dyestuffs having structures analogous to those of this invention are known from Japanese Patent Application Laid-open No. 133457/1980, it is evident, as demonstrated by the comparison data in Table 1, that the dyestuffs of this invention are far more excellent in both moisture fastness and heat resistance as well as maintain good alkali discharge printing properties.

                                      TABLE 1                                      __________________________________________________________________________                                          Alkali                                                                               Fastness after                                                           Discharge                                                                            Polyurethane Finish                                                      Printing   Perspi-  Heat                  Structural Formula                   Properties                                                                           Washing                                                                             ration                                                                             Water                                                                               Resistance            __________________________________________________________________________     Known Dyestuff 1                                                                     ##STR2##                       Grade 4-5                                                                            Grade 1-2                                                                           1-2 1-2  50                    Known Dyestuff 2                                                                     ##STR3##                       "     2    2   2    55                    Known Dyestuff 3                                                                     ##STR4##                       "     "    "   "    50                    Dyestuff of the Invention                                                            ##STR5##                       "     4-5  5   4-5  95                    Dyestuff of the Invention                                                            ##STR6##                       "     5    5   5    95                    Dyestuff of the  Invention                                                           ##STR7##                       "     4-5  5   4-5  95                    __________________________________________________________________________      Notes:                                                                         (1) Known Dyestuff 1, Known Dyestuff 2, and Known Dyestuff 3                   All described in Japanese Patent Application Laidopen No. 133457/1980.         (2) Alkali discharge printing properties                                       A dyed cloth previously dyed with the particular dyestuff was coated with      a discharge printing paste containing sodium carbonate and polyethylene        glycol (average molecular weight: 400), treated with superheated steam at      a temperature of 180° C. for 7 minutes, then reducingly washed, an      the whitness of the discharged part of the obtained dyed cloth was judged      using a gray scale for staining.                                               (3) Polyurethane finishing method                                              Curing was conducted using a 1% solution of Hydran F24 K at 160° C      for 2 minutes.                                                                 (4) Washing fastness                                                           A multifiber was attached to a dyed, polyurethanefinished cloth, and a         washing test was conducted according to AATCC Method, Washing No. IIA; th      staining of the nylon fiber of the multifiber was judged by a gray scale.      (5) Perspiration fastness                                                      A dyed, polyurethanefinished cloth was tested according to JIS L0848           Method A, using a nylon cloth and a silk cloth as attached cloths, and th      degree of staining of the silk cloth was judged by a gray scale.               (6) Water fastness                                                             A dyed, polyurethanefinished cloth was tested according to JIS L0846           Method A, except that the attached nylon cloth was replaced by a silk          cloth, and the degree of staining of the silk cloth was judged by a gray       scale.                                                                         (7) Heat resistance                                                            A dyestuff cake was mixed with a naphthalenesulfonic acidformaldehyde          condensate, and heat treated at 130° C. for an hour; the percent o      the remaining dyestuff after heat treatment was determined to judge the        heat resistance.                                                               ##STR8##                                                                 

SUMMARY OF THE INVENTION

Accordingly, this invention provides monoazo dyestuffs for polyester fibers which are of the formula [I]: ##STR9## wherein X represents hydrogen, chlorine, methyl, alkoxy or alkoxyalkoxy, Y represents hydrogen, methyl, methoxy, chlorine or acylamino, and R¹ represents C₆ -C₁₃ alkyl, C₆ -C₁₃ alkoxyethyl, C₆ -C₁₃ alkoxyethoxyethyl or benzyloxyethyl.

DETAILED DESCRIPTION OF THE INVENTION

The dyestuffs of the formula [I] above may be produced by diazotizing 2-amino-5-nitrothiazole and coupling it with an aniline of the formula [II]: ##STR10## wherein X, Y and R¹ are as defined above.

The C₆ -C₁₃ alkyl, C₆ -C₁₃ alkoxyethyl and C₆ -C₁₃ alkoxyethoxyethyl represented by R¹ may be either straight-chain or branched-chain. Examples of the alkoxy represented by X include methoxy, ethoxy, propoxy, butoxy etc.; examples of the alkoxyalkoxy include methoxyethoxy, ethoxyethoxy, butoxyethoxy etc.; and examples of the acylamino represented by Y include acetylamino, C₆ -C₁₃ alkylcarbonylamino, chloroacetylamino, benzoylamino, ethoxycarbonylamino, ethylcarbonylamino, methylsulfonylamino, chloropropionylamino etc.

Examples of fibers which can be dyed with the monoazo dyestuffs of this invention include polyester fibers composed of e.g. polyethylene terephthalate, a polycondensate of terephthalic acid and 1,4-bis-(hydroxymethyl)cyclohexane, etc., and also mixed yarns and mixed woven fabrics of natural fibers such as cotton, silk, wool etc. with the above-described polyester fibers.

Dyeing of a polyester fiber with the dyestuff of this invention may be achieved in the conventional manner, for example, by dispersing the dyestuff of the formula [I] above in an aqueous medium using a dispersing agent such as a condensate of naphthalenesulfonic acid and formaldehyde, a higher alcohol sulfuric acid ester, a higher alkylbenzenesulfonic acid salt etc. to prepare a dyeing bath or printing paste, and conducting dip dyeing or print dyeing. For example, where dip dyeing is conducted, by applying a conventional dyeing process, e.g. high temperature process, carrier process, thermosol process etc., polyester fibers or their mixed spun or mixed woven products can be dyed in colors excellent in fastness properties. In addition, even better results may sometimes be obtained by adding an acidic substance such as formic acid, acetic acid, phosphoric acid, ammonium sulfate etc. to the dyeing bath.

The monoazo dyestuffs of this invention may also be used in combination with dyestuffs of the same type or those of other type, in particular, a combination of the dyestuffs of the formula [I] above with each other sometimes gives improved results, such as enhancement of dyeing properties, etc.

This invention is more particularly described by the following examples.

EXAMPLE 1

A 0.5 g amount of a monoazo dyestuff of the formula: ##STR11## was dispersed in 3 l of water containing 1.0 g of naphthalene-sulfonic acid-formaldehyde condensate and 2 g of a higher alcohol sulfuric acid ester to prepare a dyeing bath. 100 g of a polyester cloth was dipped in this dyeing bath, and dyed at 130° C. for 60 minutes followed by soaping, washing with water and drying to obtain a yellow dyed polyester cloth having good light fastness, sublimation fastness and moisture fastness.

The dyestuff used in this example was prepared by dissolving 7.56 g of 3-N-2-ethylhexyloxycarbonylethyl-4-ethoxyacetanilide in 100 ml of methanol, adding dropwise thereto a diazo solution obtained by diazotizing 2.9 g of 5-nitro-2-aminonitrothiazole in sulfuric acid using nitrosil sulfuric acid, filtering out the separated precipitates, washing with water and drying (60% of the theoretical yield).

The λmax (acetone) of this product was 624 nm.

EXAMPLE 2

A 0.5 g amount of a dyestuff of the formula: ##STR12## was mixed with 0.5 g of a naphthalenesulfonic acid-formaldehyde condensate, and pulverized on a paint shaker to obtain a finely particulated dyestuff. This was then adequately mixed with a basal paste having the following composition:

Carboxymethyl cellulose type sizing agent: 30 g

Tartaric acid: 0.2 g

Aromatic carrier: 0.3 g

Water: 69.5 g

to obtain 100 g of a printing color paste.

A polyester fiber was print dyed with this printing color paste, provisionally dried at 100° C., then maintained in superheated steam at 170° C. for 7 minutes to develop a color, soaped, washed with water and dried to obtain a reddish blue dyed polyester cloth having good light fastness, sublimation fastness and moisture fastness.

The λmax (acetone) of this dyestuff was 565 nm.

EXAMPLE 3

Polyester fibers were dyed using the dyestuffs set forth in the following table 2 by procedures similar to those in Example 1 to obtain dyed products having hues shown in Table 2.

                                      TABLE 2                                      __________________________________________________________________________     Structural Formula                                                              ##STR13##                                                                                                                              λmax                                                             Hue    (acetone)             No. X        Y                R.sup.1             (polyester)                                                                           nm                    __________________________________________________________________________     1   OCH.sub.3                                                                               NHCOCH.sub.3     CH.sub.2 CH(C.sub.2 H.sub.5)C.sub.4 H.sub.9                                    (n)                 Greenish                                                                              624                                                                     Blue                         2   "        "                C.sub.6 H.sub.13 (n)                                                                               Greenish                                                                              "                                                                       Blue                         3   "        "                C.sub.8 H.sub.17 (n)                                                                               Greenish                                                                              "                                                                       Blue                         4   "        "                C.sub.9 H.sub.19 (n)                                                                               Greenish                                                                              "                                                                       Blue                         5   "        "                C.sub.10 H.sub.21 (n)                                                                              Greenish                                                                              "                                                                       Blue                         6   "        "                C.sub.12 H.sub.25 (n)                                                                              Greenish                                                                              "                                                                       Blue                         7   "        "                C.sub.13 H.sub.27 (n)                                                                              Greenish                                                                              "                                                                       Blue                         8   OC.sub.2 H.sub.5                                                                        "                C.sub.8 H.sub.17 (n)                                                                               Greenish                                                                              "                                                                       Blue                         9   "        "                C.sub.9 H.sub.19 (n)                                                                               Greenish                                                                              "                                                                       Blue                         10  "        "                C.sub.10 H.sub.21 (n)                                                                              Greenish                                                                              "                                                                       Blue                         11  "        "                C.sub.12 H.sub.25 (n)                                                                              Greenish                                                                              "                                                                       Blue                         12  "        "                C.sub.13 H.sub.27 (n)                                                                              Greenish                                                                              "                                                                       Blue                         13  "        NHCOC.sub.2 H.sub.5                                                                             CH.sub.2 CH(C.sub.2 H.sub.5)C.sub.4 H.sub.9                                    (n)                 Greenish                                                                              "                                                                       Blue                         14  "        NHCOCH.sub.3                                                                                     ##STR14##          Greenish Blue                                                                         621                   15  OCH.sub.3                                                                               "                "                   Greenish                                                                              "                                                                       Blue                         16  "        "                C.sub.2 H.sub.4 OC.sub. 6 H.sub.13 (n)                                                             Greenish                                                                              623                                                                     Blue                         17  "        "                C.sub.2 H.sub.4 OC.sub.12 H.sub.25 (n)                                                             Greenish                                                                              "                                                                       Blue                         18  OC.sub.2 H.sub.5                                                                        "                C.sub.2 H.sub.4 OC.sub.6 H.sub.13 (n)                                                              Greenish                                                                              "                                                                       Blue                         19  "        "                C.sub.2 H.sub.4 OC.sub.12 H.sub.25 (n)                                                             Greenish                                                                              "                                                                       Blue                         20  OCH.sub.3                                                                               "                C.sub.2 H.sub.4 OC.sub.2 H.sub.4 OC.sub.6                                      H.sub.13 (n)        Greenish                                                                              "                                                                       Blue                         21  "        "                C.sub.2 H.sub.4 OC.sub.2 H.sub.4 OCH.sub.2                                     CH(C.sub.2 H.sub.5)C.sub.4 H.sub.9 (n)                                                             Greenish                                                                              "                                                                       Blue                         22  "        "                C.sub.2 H.sub.4 OC.sub.2 H.sub.4 OC.sub.12                                     H.sub.25 (n)        Greenish                                                                              "                                                                       Blue                         23  OC.sub.2 H.sub.5                                                                        "                C.sub.2 H.sub.4 OC.sub.2 H.sub.4 OC.sub.10                                     H.sub.21 (n)        Greenish                                                                              "                                                                       Blue                         24  "        "                C.sub.2 H.sub.4 OC.sub.2 H.sub.4 OC.sub.6                                      H.sub.13 (n)        Greenish                                                                              "                                                                       Blue                         25  "        "                C.sub.2 H.sub.4 OC.sub.2 H.sub.4 OC.sub.12                                     H.sub.25 (n)        Greenish                                                                              "                                                                       Blue                         26  "        "                C.sub.2 H.sub.4 OC.sub.2 H.sub.4 OC.sub.13                                     H.sub.27 (n)        Greenish                                                                              "                                                                       Blue                         27  OC.sub.2 H.sub.4 OCH.sub.3                                                              "                CH.sub.2 CH(C.sub.2 H.sub.5)C.sub.4 H.sub.9                                    (n)                 Greenish                                                                              "                                                                       Blue                         28  "        NHCOC.sub.2 H.sub.5                                                                             "                   Greenish                                                                              "                                                                       Blue                         29  OC.sub.2 H.sub.5                                                                        NHCOCH.sub.2 CH(C.sub.2 H.sub.5)C.sub.4 H.sub.9 (n)                                             "                   Greenish                                                                              "                                                                       Blue                         30  OC.sub.2 H.sub.4 OCH.sub.3                                                              NHCOCH.sub.3                                                                                     ##STR15##          Greenish Blue                                                                         621                   31  OC.sub.2 H.sub.4 OC.sub.4 H.sub.9                                                       "                "                   Greenish                                                                              "                                                                       Blue                         32  "        "                CH.sub.2 CH(C.sub.2 H.sub.5)C.sub.4 H.sub.9                                    (n)                 Greenish                                                                              624                                                                     Blue                         33  "        "                C.sub.6 H.sub.13 (n)                                                                               Greenish                                                                              "                                                                       Blue                         34  Cl       "                "                   Reddish                                                                               565                                                                     Blue                         35  "        "                C.sub.7 H.sub.15 (n)                                                                               Reddish                                                                               "                                                                       Blue                         36  "        "                C.sub.8 H.sub.17 (n)                                                                               Reddish                                                                               "                                                                       Blue                         37  "        "                C.sub.9 H.sub.19 (n)                                                                               Reddish                                                                               "                                                                       Blue                         38  "        "                C.sub.10 H.sub.21 (n)                                                                              Reddish                                                                               "                                                                       Blue                         39  "        "                C.sub.12 H.sub.25 (n)                                                                              Reddish                                                                               "                                                                       Blue                         40  "        "                C.sub.13 H.sub.27 (n)                                                                              Reddish                                                                               "                                                                       Blue                         41  "        "                                                                                                ##STR16##          Reddish  Blue                                                                         562                   42  "        "                C.sub.2 H.sub.4 OC.sub.6 H.sub.13 (n)                                                              Reddish                                                                               564                                                                     Blue                         43  "        "                C.sub.2 H.sub.4 OC.sub.12 H.sub.25 (n)                                                             Reddish                                                                               "                                                                       Blue                         44  "        "                C.sub.2 H.sub.4 OC.sub.2 H.sub.4 OC.sub.6                                      H.sub.13 (n)        Reddish                                                                               "                                                                       Blue                         45  "        "                C.sub.2 H.sub.4 OC.sub.2 H.sub.4 OC.sub.12                                     H.sub.25 (n)        Reddish                                                                               "                                                                       Blue                         46  "        NHCOC.sub.2 H.sub.5                                                                             CH.sub.2 CH(C.sub.2 H.sub.5)C.sub.4 H.sub.9                                    (n)                 Reddish                                                                               565                                                                     Blue                         47  "        NHCOCH.sub.2 CH(C.sub.2 H.sub.5)C.sub.4 H.sub.9 (n)                                             "                   Reddish                                                                               "                                                                       Blue                         48  CH.sub.3 NHCOCH.sub.3     "                   Blue   587                   49  "        "                C.sub.6 H.sub.13 (n)                                                                               "      "                     50  "        "                C.sub.8 H.sub.17 (n)                                                                               "      "                     51  "        "                C.sub.9 H.sub.19 (n)                                                                               "      "                     52  "        "                C.sub.10 H.sub.21 (n)                                                                              "      "                     53  "        "                C.sub.11 H.sub.23 (n)                                                                              "      "                     54  "        "                C.sub.12 H.sub.25 (n)                                                                              "      "                     55  "        "                C.sub.13 H.sub.27 (n)                                                                              "      "                     56  "        "                CH(CH.sub.3)C.sub.6 H.sub.13 (n)                                                                   "      "                     57  "        NHCOC.sub.2 H.sub.5                                                                             CH.sub.2 CH(C.sub.2 H.sub.5)C.sub.4 H.sub.9                                    (n)                 "      "                     58  "        NHCOCH.sub.2 CH(C.sub.2 H.sub.5)C.sub.4 H.sub.9                                                 "                   "      "                     59  "        NHCOCH.sub.3                                                                                     ##STR17##          "      584                   60  "        "                C.sub.2 H.sub.4 OC.sub.6 H.sub.13 (n)                                                              "      586                   61  "        "                C.sub.2 H.sub.4 OC.sub.12 H.sub.25 (n)                                                             "      "                     62  "        "                C.sub.2 H.sub.4 OC.sub.2 H.sub.4 OC.sub.6                                      H.sub.13 (n)        "      "                     63  "        "                C.sub.2 H.sub.4 OC.sub.2 H.sub.4 OC.sub.12                                     H.sub.25 (n)        "      "                     64  H        "                C.sub.6 H.sub.13 (n)                                                                               "      583                   65  "        "                C.sub.7 H.sub.15 (n)                                                                               "      "                     66  "        "                C.sub.8 H.sub.17 (n)                                                                               "      "                     67  "        "                C.sub.9 H.sub.19 (n)                                                                               "      "                     68  "        "                CH.sub.2 CH(C.sub.2 H.sub.5)C.sub.4 H.sub.9                                    (n)                 "      "                     69  "        "                C.sub.10 H.sub.21 (n)                                                                              "      "                     70  "        "                C.sub.12 H.sub.25 (n)                                                                              "      "                     71  "        "                C.sub.13 H.sub.27 (n)                                                                              "      "                     72  "        NHCOC.sub.2 H.sub.5                                                                             CH.sub.2 CH(C.sub.2 H.sub.5)C.sub.4 H.sub.9                                    (n)                 "      "                     73  "        NHCOCH.sub.3                                                                                     ##STR18##          Reddish Blue                                                                          579                   74  "        "                C.sub.2 H.sub.4 OC.sub.6 H.sub.13 (n)                                                              Blue   582                   75  "        "                C.sub.2 H.sub.4 OC.sub.12 H.sub.25 (n)                                                             "      "                     76  "        "                C.sub.2 H.sub.4 OC.sub.2 H.sub.4 OC.sub.6                                      H.sub.13 (n)        "      "                     77  "        "                C.sub.2 H.sub.4 OC.sub.2 H.sub.4 OC.sub.12                                     H.sub.25 (n)        "      "                     78  OCH.sub.3                                                                               CH.sub.3         CH.sub.2 CH(C.sub.2 H.sub.5)C.sub.4 H.sub.9                                    (n)                 "      615                   79  "        "                C.sub.6 H.sub.13 (n)                                                                               "      "                     80  "        "                C.sub.8 H.sub.17 (n)                                                                               "      "                     81  "        "                                                                                                ##STR19##          "      612                   82  "        "                C.sub.2 H.sub.4 OC.sub.6 H.sub.13 (n)                                                              "      614                   83  "        "                C.sub.2 H.sub.4 OC.sub.12 H.sub.25 (n)                                                             "      "                     84  "        "                C.sub.2 H.sub.4 OC.sub.2 H.sub.4 OC.sub.6                                      H.sub.13 (n)        "      "                     85  "        "                C.sub.2 H.sub.4 OC.sub.2 H.sub.4 OC.sub.12                                     H.sub.25 (n)        "      "                     86  "        OCH.sub.3        C.sub.6 H.sub.13 (n)                                                                               Greenish                                                                              625                                                                     Blue                         87  "        "                CH.sub.2 CH(C.sub.2 H.sub.5)C.sub.4 H.sub.9                                    (n)                 Greenish                                                                              "                                                                       Blue                         88  "        "                                                                                                ##STR20##          Greenish Blue                                                                         622                   89  "        "                C.sub.2 H.sub.4 OC.sub.6 H.sub.13 (n)                                                              Greenish                                                                              624                                                                     Blue                         90  "        "                C.sub.2 H.sub.4 OC.sub.12 H.sub.25 (n)                                                             Greenish                                                                              "                                                                       Blue                         91  "        "                C.sub.2 H.sub.4 OC.sub.2 H.sub.4 OC.sub.6                                      H.sub.13 (n)        Greenish                                                                              "                                                                       Blue                         92  "        "                C.sub.2 H.sub.4 OC.sub.2 H.sub.4 OC.sub.12                                     H.sub.25 (n)        Greenish                                                                              "                                                                       Blue                         93  "        "                C.sub.8 H.sub.17 (n)                                                                               Greenish                                                                              "                     94  "        "                C.sub.10 H.sub.21 (n)                                                                              Greenish                                                                              "                                                                       Blue                         95  CH.sub.3 CH.sub.3         CH.sub.2 CH(C.sub.2 H.sub.5)C.sub.4 H.sub.9                                    (n)                 Reddish                                                                               587                                                                     Blue                         96  "        "                                                                                                ##STR21##          Reddish Blue                                                                          584                   97  "        "                C.sub.2 H.sub.4 OC.sub.6 H.sub.13 (n)                                                              Reddish                                                                               586                                                                     Blue                         98  "        "                C.sub.2 H.sub.4 OC.sub.12 H.sub.25 (n)                                                             Reddish                                                                               "                                                                       Blue                         99  "        "                C.sub.2 H.sub.4 OC.sub.2 H.sub.4 OC.sub.6                                      H.sub.13 (n)        Reddish                                                                               "                                                                       Blue                         100 H        "                CH.sub.2 CH(C.sub.2 H.sub.5)C.sub.4 H.sub.9                                    (n)                 Reddish                                                                               582                                                                     Blue                         101 "        "                                                                                                ##STR22##          Reddish Blue                                                                          579                   102 "        "                C.sub.2 H.sub.4 OC.sub.6 H.sub.13 (n)                                                              Reddish                                                                               581                                                                     Blue                         103 "        "                C.sub.8 H.sub.17 (n)                                                                               Reddish                                                                               582                                                                     Blue                         104 "        "                C.sub.2 H.sub.4 OC.sub.12 H.sub.25 (n)                                                             Reddish                                                                               581                                                                     Blue                         105 "                                                                                        ##STR23##       CH.sub.2 CH(C.sub.2 H.sub.5)C.sub.4 H.sub.9                                    (n)                 Blue   "                     106 "        "                                                                                                ##STR24##          Reddish Blue                                                                          577                   107 "        "                C.sub.6 H.sub.13 (n)                                                                               Blue   581                   108 "        NHSO.sub.2 CH.sub.3                                                                             "                   Reddish                                                                               577                                                                     Blue                         109 "        "                CH.sub.2 CH(C.sub.2 H.sub.5)C.sub.4 H.sub.9                                    (n)                 Reddish                                                                               "                                                                       Blue                         110 "        NHCOC.sub.2 H.sub.4 Cl                                                                          "                   Blue   583                   111 "        NHCOCH.sub.2 Cl  "                   "      581                   112 "        NHCOOC.sub.2 H.sub.5                                                                            "                   Reddish                                                                               576                                                                     Blue                         113 "        NHCONHC.sub.2 H.sub.5                                                                           "                   Blue   583                   114 "        H                "                   Reddish                                                                               572                                                                     Blue                         115 "        "                C.sub.10 H.sub.21 (n)                                                                              Reddish                                                                               "                                                                       Blue                         116 "        "                                                                                                ##STR25##          Reddish Blue                                                                          568                   117 "        "                C.sub.2 H.sub.4 OC.sub.6 H.sub.13 (n)                                                              Reddish                                                                               571                                                                     Blue                         118 "        "                C.sub.2 H.sub.4 OC.sub.12 H.sub.25 (n)                                                             Reddish                                                                               "                                                                       Blue                         119 "        Cl               CH.sub.2 CH(C.sub.2 H.sub.5)C.sub.4 H.sub.9                                    (n)                 Reddish                                                                               569                                                                     Blue                         120 "        "                C.sub.6 H.sub.13 (n)                                                                               Reddish                                                                               "                                                                       Blue                         121 "        "                C.sub.2 H.sub.4 OC.sub.6 H.sub.13 (n)                                                              Reddish                                                                               568                                                                     Blue                         __________________________________________________________________________ 

What is claimed is:
 1. A monoazo dyestuff of the formula: ##STR26## wherein X represents hydrogen, chlorine, methyl, methoxy or ethoxy; Y represents methyl, acetylamino or propionylamino; and R¹ represents C₈ -C₁₀ alkyl.
 2. The monoazo dyestuff of claim 1, wherein Y is acetylamino and X and R¹ are as defined in claim
 1. 3. The monoazo dystuff of claim 1, wherein R¹ is C₈ alkyl and X and Y are as defined in claim
 1. 4. A monoazo dyestuff of the formula: ##STR27##
 5. A monoazo dyestuff of the formula: ##STR28## 